JP2002257813A - Food quality indicator, packaging paper for food and packaging container for food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a food quality indicator, a packaging paper for food and a packaging container for food whereby a degree of aging of the food can be identified correctly from the outside without opening a package. SOLUTION: The food quality indicator is composed of an indicator which changes its color in accordance with a pH value, a resin monomer having a double bond for immobilizing the indicator, a polymer hydrogel matrix formed of a crosslinking agent and, a semipermeable membrane for passing only ions and a solvent selectively. The matrix is adhered to at least one point of one surface of the semipermeable membrane. There are also provided the packaging paper for food and the packaging container for food which have the food quality indicator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indicator for identifying and displaying the quality of food, a food packaging paper, and a food packaging container.

[0002]

2. Description of the Related Art Kimchi is a Korean food. Kimchi is generally salted Chinese cabbage, and radish, various vegetables and seasoning ingredients mixed with seasonings are evenly squeezed between salted Chinese cabbage leaves and stored in a container.
It is a fermented food that is fermented and matured over time, and can be eaten with the maturity adjusted according to consumer preference.

[0003] Such kimchi is commonly cooked and eaten in Korean households, and there are various ways to make it, and the kind thereof is slightly different depending on the region and eating habits.

In recent years, simplicity of eating habits has been demanded,
The development of ready-to-eat foods has been accelerated, and the packaging technology has been developed in various ways for packaging various foods.

[0005] Kimchi packaging is a food product of which the degree of maturity by fermentation is a preference, and thus it has been conventionally distributed in a vacuum packaging form with a distribution period indicated. As various international events and international trips have increased, kimchi is becoming recognized as a representative Korean food in foreign countries.

Especially in Japan, kimchi has been widely commercialized,
Research reports from the academic community that fermented foods are beneficial to health and introductions by the media have been made. In recent years, the export of kimchi has greatly increased, and it has been spotlighted as an internationalized fermented food.

[0007] Conventional kimchi packaging uses vacuum wrapping paper made of a general resin in order to maintain the merchantability by delaying ripening in the distribution process while keeping the taste of the consumer, and using the packaging form. Were various.

[0008]

However, conventional kimchi packaging is packaged in a vacuum or hermetically sealed state regardless of its form, so once opened, it comes into contact with air to accelerate fermentation and ripening. , Over time, it will be overripe and sour. For this reason, once opened, they had to eat early.

In addition, since the ripening degree of kimchi is not known from the outside, some kimchi wrapping products are distributed with the ripening degree indicated on wrapping paper. Since the ripening progressed inconsistently, the exact ripening degree and taste could not be known without opening the packaging.

As described above, the conventional kimchi packaged product is
As ripening progresses in the distribution process and the ripening degree and taste cannot be confirmed before opening the package, it is difficult for consumers to select products that match their tastes, and it is not easy for sellers to manage products. There was a problem.

[0011] Further, for the above reasons, it is difficult to maintain good product quality, and there are difficulties in packaging distribution and quality control of mass-produced kimchi in factories, so that product reliability cannot be guaranteed. As such, there has been a problem that internationalized fermented foods cannot meet the needs of various consumers.

Therefore, the present invention can accurately identify the degree of maturity of food from the outside without opening the package, and can select a product that suits the taste of the consumer. To improve the quality of products, to facilitate the distribution and quality control of mass-produced kimchi in factories, to assure product reliability, and to meet the needs of various consumers. An object of the present invention is to provide a food quality indicator, a food wrapping paper and a food packaging container.

[0013]

Means for Solving the Problems The present inventor worked diligently to solve the above-mentioned problems in the distribution process of the conventional kimchi packaged product and the problem of consumer product selection. Focusing on the fact that the pH changes depending on the fermentation and ripening degree, and by including a pH-sensitive substance in the kimchi packaging, the kimchi ripening level can be sensed and the kimchi ripening level, taste, etc. Of the present invention, which can be recognized from the outside.

That is, the food quality indicator of the present invention for solving the above-mentioned problems comprises an indicator that changes color according to a pH value, a resin monomer having a double bond for fixing the indicator, and a crosslinking agent. And a semipermeable membrane that selectively permeates only ions and solvents, wherein the matrix is attached to at least one location on one surface of the semipermeable membrane. With such a configuration of the invention, the maturity of the food in contact with the indicator can be identified.

[0015] The indicator can be appropriately selected depending on the target food, and for example, methyl orange, meta-cresol purple, or a mixture thereof can be used.

The resin monomer can be selected from, for example, dimethylacrylamide, hydroxyethyl methacrylate, or a mixture of two or more thereof. Such an acrylic resin monomer is added with a crosslinking agent, for example, at a content ratio of 15 to 20% by weight based on the total amount of the matrix, and then crosslinked. Then, a pH indicator is added to the total amount of the matrix, for example. To 2 to 5% by weight. If the content of the pH indicator is too large, the color becomes too dark and it becomes difficult to distinguish the color. On the other hand, if the content is too small, there is a problem that the color change color is covered by the hue of the polymer matrix.

The cross-linking agent may contain, for example, one or more selected from ethylene glycol dimethyl acrylamide, divinyl sulfone, and methylene bisacrylamide. If the content of the cross-linking agent is too high, the color change may be delayed in time, while if the content of the cross-linking agent is too low, the mechanical strength of the matrix deteriorates, or a pH indicator having a small molecular weight is used. There is a problem of release.

As described above, when a matrix is prepared with each component in an appropriate content, the degree of fixation of the pH indicator to be added is determined according to the degree of crosslinking of the hydrogel formed by the monomer and the crosslinking agent. The degree of cross-linking can be adjusted by changing the type and amount of the cross-linking agent, and the degree of fixation can be optimized.

The semipermeable membrane is made of, for example, cellulose ester,
Alternatively, regenerated cellulose or the like can be used. Such a semipermeable membrane transmits only ions and solvents having a molecular weight within 100 and does not transmit other solutes. The area of the semi-permeable membrane may be an area corresponding to a portion where the matrix attached to one surface thereof is attached, or an area sufficient for ions and a solvent to permeate and contact the matrix. The semi-permeable membrane may be prepared separately for each matrix,
One translucent film may be shared by a plurality of matrices.

Further, the food quality indicator of the present invention comprises:
Composed of two or more polymer hydrogel matrices each using two or more indicators that change color at different pH values, and one or more semi-permeable membranes that selectively permeate only ions and solvents Is also good. With this configuration, the amount of information on the maturity of the food increases.

Further, the food wrapping paper of the present invention for solving the above-mentioned problem is provided with the food quality indicator having the above-mentioned configuration, and the object to be wrapped comes into contact with the semi-permeable membrane, and the ions and the ions permeating through the semi-permeable membrane are provided. The solvent is in contact with the matrix so that the matrix can be observed from the outside.

The food wrapping paper of the present invention is prepared, for example, by dissolving a resin monomer containing a pH indicator in water at 30% by weight to form an aqueous solution, mixing a cross-linking agent, and then adding Teflon (registered trademark) at room temperature for 3 minutes. ) In a mold made by polymerization, a matrix is formed. The unreacted material is washed with water. This matrix is sandwiched between a base film such as polyethylene or polypropylene film and a semi-permeable membrane. Can be manufactured by a so-called heat sealing method of thermocompression bonding.

The food wrapping paper of the present invention may use an aluminum-coated plastic film as a base film. The application form is, for example, to make a certain part of the wrapping paper transparent, affix the food quality indicator of the present invention from the back of the wrapping paper, or to open a part of the wrapping paper,
The food quality indicator of the present invention can be affixed to the opening from the surface, and can be variously applied in consideration of the conditions of the wrapping paper.

If the food quality indicator having the above structure is fixed on a frame or the like and placed on a food to check the color change, or if it is applied to a packaging container, a packaging bag, a packaging pack, etc., a product distribution route is obtained. It can be used not only at home but also at home.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the food quality indicator and the food wrapping paper of the present invention will be described in detail with reference to specific embodiments.

FIG. 1 is a diagram showing an embodiment of a food quality indicator of the present invention and an embodiment of a food wrapping paper of the present invention having the same. The food wrapping paper 1 includes a polymer hydrogel matrix 2 and a semi-permeable membrane 3 that selectively allows only ions and solvents to pass therethrough. A food quality indicator 4 having two unit configurations attached to one place is attached.

[0027] For example Kimchi, if packaged in this food wrap 1 as a semi-permeable membrane 3 are in direct contact, OH are dissolved in juice Kimchi ^- ions semipermeable membrane through the semi-permeable membrane 3 The matrix 2 adheres to 3 and the color of the matrix changes or does not change according to the pH value of the kimchi.
The range of the pH value can be determined from the color change unique to the matrix, and the pH of the kimchi, that is, the maturity of the packaged kimchi can be identified in real time.

In general, kimchi is acidified as the fermentation proceeds, and the pH value decreases. Unripe kimchi has a pH of 6 to 4.5 and properly ripened kimchi has a pH of
4.5-3, overripe kimchi is reported to have a pH of 3-2.5, and rotten kimchi is reported to have a pH of 2.5-2 or less.

For example, if meta-cresol purple and methyl orange are used as indicators and an indicator having both a polymer hydrogel matrix with each indicator immobilized is used, the polymer hydrogel matrix with the indicator immobilized will have a different pH. Since the color changes rapidly at the boundary points, the four stages of the kimchi maturity can be identified.

FIG. 2 shows an indicator 2 composed of a matrix 22a having meta-cresol purple fixed on the left and a matrix 22b having methyl orange fixed on the right.
FIG. 4 is a view showing a color change corresponding to four stages of maturity of kimchi.

In FIG. 2, in order from the top, according to the degree of maturity of the kimchi, "Kimchi not yet ripe" (freshly made kimchi-yellow, yellow), "appropriate ripe kimchi" (kimchi with good taste) Yellow, birch), "Excessively ripe kimchi"
(Sour Kimchi-Birch, Birch), "Rotten Kimchi"
The state of the color change is shown (to be discarded-red, red).

According to the food quality indicator and the food wrapping paper of the present embodiment, the quality of the packaged kimchi such as the maturity and taste can be identified at a glance by observing the color change from outside without opening the package. Consumers who want to purchase packaging products with this can purchase the desired products according to their preferences, and producers and sellers can manage sales and distribution according to the quality of kimchi. , It can greatly improve the kimchi's merchantability and reliability.

Further, the food quality indicator of the present embodiment can be applied to vacuum wrapping paper in a kimchi manufacturing plant.
Further, the present invention can be applied to ordinary aluminum cans, plastic packaging containers and the like with appropriate modification.

The present invention is also applicable to a sealing pack or a plastic bag widely used in ordinary households. When kimchi or other fermented foods or refrigerated foods are stored in the packs and the like, the contents are aged. Very convenient because the degree can be easily identified. Such packs can be used as many times as they are washed.

Although the present invention has been described in detail based on the embodiments, the present invention is not limited to these examples.
It is obvious that a person skilled in the art can conceive various changes or modifications within the scope of the technical idea described in the claims. It is understood that it belongs to.

Although kimchi has been described as an example of food, the invention is not limited to this.
As long as H changes, it can be applied to any of them.

[0037]

As described above, according to the present invention, when the present invention is applied to food packaging, the degree of maturity of the food can be easily identified from the outside of the packaging by color change. The quality of the prepared food, such as maturity and taste, can be identified at a glance. Therefore, consumers can purchase foods of the desired quality, and producers and sellers can sell and distribute them according to the state of the quality. The reliability can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a food quality indicator and food wrapping paper according to an embodiment.

FIG. 2 shows the food quality indicator according to the embodiment;
It is a figure which shows the color change corresponding to four stages of maturity of kimchi.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wrapping paper for foods 2, 22a, 22b Polymer hydrogel matrix 3, 23 Semi-permeable membrane 4, 24 Food quality indicator

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01N 1/10 G01N 1/10 B 3E067 21/80 21/80 4B069 31/22 123 31/22 123 F term (Ref.) BA04 BB02 CA16 CE02 EA05 EA06 FA06 GB04 GE06 GE07 JA02 3E035 AA20 AB10 BB10 3E062 AB14 BA07 BB02 BB09 DA02 3E067 AB01 BA17A BB01A EE18 EE21 EE28 GD10 4B069 DA19 DA20 HA02 HA09

Claims (8)

[Claims] 1. An indicator that changes color according to a pH value, a resin monomer having a double bond for fixing the indicator,
And a polymer hydrogel matrix comprising a cross-linking agent and a semi-permeable membrane that selectively permeates only ions and solvents, wherein the matrix is attached to at least one location on one surface of the semi-permeable membrane. Features food quality indicator. 2. The food quality indicator according to claim 1, wherein the resin monomer comprises dimethylacrylamide, hydroxyethyl methacrylate, or a mixture thereof. 3. The food quality indicator according to claim 1, wherein the crosslinking agent comprises one or more components selected from ethylene glycol dimethyl acrylamide, divinyl sulfone, and methylene bisacrylamide. 4. The semi-permeable membrane according to claim 1, wherein the translucent membrane is a cellulose ester,
The food quality indicator according to claim 1, wherein the food quality indicator is made of regenerated cellulose. 5. The area of the semi-permeable membrane is an area corresponding to a place where the matrix adheres to one side thereof, or an area sufficient for permeation of ions and solvents and contact with the matrix. The food quality indicator according to claim 1, characterized in that: 6. Two or more polymer hydrogel matrices, each using two or more indicators that change color at different pH values, and one selectively permeating only ions and solvents.
A food quality indicator, comprising: one or a plurality of semi-permeable membranes, wherein the two or more types of matrices are respectively attached to at least one location on one surface of the semi-permeable membrane. 7. A food quality indicator according to any one of claims 1, 2, 3, 4, 5, and 6, wherein an object to be packaged contacts the semi-permeable membrane, and The ions and the solvent permeating the membrane come into contact with the matrix,
A food wrapping paper characterized in that the matrix can be observed from the outside. 8. A food packaging container comprising the food quality indicator according to any one of claims 1, 2, 3, 4, 5, and 6.